This invention relates to a longwall mineral mining installation.
A known type of longwall mineral mining installation has a face conveyor which extends along a longwall working. At each end, the working merges with a roadway or gallery which extends substantially at right-angles thereto. A plough guide is attached to the face-side of the conveyor and a plough is movable to and fro along the guide. The plough is driven, via a sword plate extending under the conveyor and a goaf-side endless drive chain attached to the sword plate, by means of a drive situated at one end of the conveyor. Such an installation may also have a second plough which is also movable to and fro along the plough guide. In this case, the two ploughs are independently operable so that the capacity of the face conveyor can be utilised as fully as possible. The use of two ploughs also enables mineral material to be won, from faces having seams of differing hardness or zones containing deformities, at the same rate as that possible using a single plough on faces having uniform, uninterrupted seams. The drives for the two ploughs are arranged one at each end of the conveyor, that is to say in the end zones of the working where the conveyor drives are situated. Consequently, the already constricted end zones of the longwall conveyor are further congested, particularly as both ploughs have to be designed to deal with the same high winning capacity, and so require large and robust drives. Another disadvantage of such an installation, is that the end (stable-hole) zones of the working have to be excavated by hand. Alternatively, if the conveyor were extended so that the ploughs could win material over the entire length of the longwall face, the heavy drives for the conveyor and the ploughs would have to be situated in the roadways, and this is disadvantageous because the roadway roof support systems would have to be opened up each time the conveyor is advanced to follow up the advance of the face. Furthermore, the two ploughs require drive chains and chain guides that extend the entire length of the conveyor, and this involves an extremely expensive construction and makes repair and maintenance work rather difficult. (DE-OS No. 2 439 259 describes such an installation).
In order to obviate the need to excavate the stable-hole regions by hand, another known type of longwall mineral mining installation has an extended face conveyor. The end extensions of the conveyor are curved and terminate in the roadways. The disadvantage of this type of installation is that the roadways are completely filled up with machinery in the access zones to the longwall working. Moreover, when the conveyor is advanced, the roadway roof support systems have to be opened up. (see DE-AS No. 1 280 782).
The aim of the invention is to provide a longwall mineral mining installation that can win material in the stable-hole regions of a longwall working, without leading to excessive machinery congestion in the zones where the working meets the access roadways.